Conformable elastic adhesive tape

ABSTRACT

A method for producing and the product thereof comprising a conformable elastic pressure-sensitive adhesive tape including a low modulus woven elastic backing weighing, when relaxed, in the range of 100 to 300 grams per square yard and incorporating distributed warp yarns with elastomeric cores in the ratio range of from 1 such warp yarn in three to one in 6 total warp yarns, which distributed warp yarns cause the major surfaces of the backing when relaxed to assume a nonplanar character including intermingled raised and depressed areas, and a layer of pressuresensitive adhesive substantially conforming with and adherent to one of the major surfaces of the backing, major surfaces of the tape becoming more nearly planar upon being stretched, specific embodiments of the tape possessing breathability, transverse hand-tearability, high strength and ready unrollability with its backing and adhesive surfaces in contact.

0 United States Patent l 13,618,754

[72] lnventor Raymond M. lloey 3,332,416 7/1967 Brickman et a1 1 17/7 XHarrington, 111. 3,523,528 8/1970 Patience et a1. 128/ 169 [2]] P 798300Primary Examiner-William D. Martin [22] Filed Feb. 11, 1969 AssistantExaminer-Theodore G. Davis [45] Patented I971 Attorneys-Jamal Fawcettand Robert D Chodera [73] Assignee The Kendall Company Walpole, Mass.

[54] CONFORMABLE ELASTIC ADHESIVE TAPE 15 Claims, 6 Drawing Figs.

[52] U.S.Cl... 206/59C 117/7. 117/122 P. 161/73, 161/77. 161/91.

[51] lnt.Cl...t,.. C09j 7/04 [50] FieldofSearch 7/7, 122 P, 122 A, 122PA,122 PS,122 PB; 161/73, 77, 91, 167; 128/156. 169; 206/59C ABSTRACT: Amethod for producing and the product thereof comprising a conformableelastic pressure-sensitive adhesive tape including a low modulus wovenelastic backing weighing. when relaxed. in the range of 100 to 300 gramsper square yard and incorporating distributed warp yarns with elastomer-1c cores in the ratio range of from 1 such warp yarn in three to one in6 total warp yarns, which distributed warp yarns cause the majorsurfaces of the backing when relaxed to assume a nonplanar characterincluding intermingled raised and depressed areas, and a layer ofpressure-sensitive adhesive substantially conforming with and adherentto one of the major surfaces of the backing, major surfaces of the tapebecoming more nearly planar upon being stretched, specific embodimentsof the tape possessing breathability, transverse hand-tearability, highstrength and ready unrollability with its backing and adhesive surfacesin contact,

CONFORMABLE ELASTIC ADHESIVE TAPE This invention is concerned withconformable elastic pressure-sensitive adhesive tapes and with a methodof producing them.

BACKGROUND OF THE INVENTION For many years it has been the practice asan effective protective measure to wrap vulnerable portions of thebodies of athletes with strengthening ribbonlike bands prior to theirparticipation in strenuous and highly competitive games and contactsports where sprains, dislocations and other severe injuries to jointsand muscles may be anticipated. These wrappings have been of variouskinds, the most unsophisticated of which have been simply rolls of heavycotton cloth ribbons.

One of the older type bandages still being used is an all cotton bandagewith some degree of stretch imparted by the use of high twist S and Zyarns as the warp yarns. A variation of this bandage is lightly coatedwith a pressure sensitive adhesive.

Another commonly used wrapping is ordinary cotton cloth backed adhesivetape, which normally may be wrapped from the roll and torn with thefingers. Variations from simple cloth wrappings of cotton have includedbandages in which the warp yarns have been stretch nylon, as isexemplified in U.S. Pat. No. 2,810,184. The retractive force of suchwrappings obviously is very, very low. Therapeutic bandages in which allof the warp yarns have been spandex corespun or elastomericcore wrappedyarns, as is exemplified in U.S. Pat. No. 3,409,008, have been usedlargely where an injury has already been received. Although relativelylight, the specific bandage referred to is a true compression bandagehaving high power, high elongation and high recovery but with a lenorather than a selvage edge. Among the more elaborate compression orconstriction wrappings which are generally wrapped with considerabletension have been relatively bulky woven elastic bandages with selvages.Another compression type of wrapping is illustrated and described inU.S. Pat. No. 2,740,402, in which the described construction is foamlatex interiorly reinforced with spaced elastic strands. An embodimentof this compression bandage is coated with pressure sensitive adhesive.Another older-type bandage, a composite fabric of knitted material andsheet rubber, is illustrated and described in U.S. Pat. No. 2,077,5 l4.

SUMMARY OF THE INVENTION This invention is concerned with confonnableelastic pressure-sensitive adhesive tapes and with a method of producingthem. The adhesive tapes of the invention have wide utility as generalathletic tapes, as hospital tapes, and for protective wrappings forinjured or vulnerable portions of the body, particularly the bodyjoints, but the conformability, light weight and elasticity which all ofthe tapes possess, and the tearability, breathability and high strengthfeatures which some embodiments possess, make them useful for a widevariety of taping and wrapping operations in which the durability andflexibility of cloth is preferred over elastic film-backed tapes or overextensible conformable paper tapes.

The adhesive tapes of this invention are not critical as to the type ofpressure sensitive adhesive which is suitable, but the thickness of theadhesive may be a consideration if lightweight, breathability orimperviousness are important. The tapes of the invention include wovenelastic backings readily stretched to a length at least 2.2 times theunstretched relaxed length by a force of about 0.3 to 1.0 pounds perinch width, weighing from about 100 grams to about 300 grams per squareyard and containing distributed elastomeric-core covered yarns eithercorespun or wrapped core. The elastomeric material is not criticalalthough spandex is preferred, with cores ranging from 40 to 140 denierbeing suitable. The core covering material is not critical. Theelastomeric warp yarns are distributed among other flexible warp yarnspreferably but not essentially in an ordered arrangement across thefabric. The warp yarns may vary in sizes equivalent to cotton from l0sto 's preferably but not necessarily of substantially uniform size. Thefabric is woven with a combined ends per inch from about 18 to about 40with a preferred ends per inch of about 32. The filling yarns areflexible but not critical as to material. The picks per inch may rangefrom about 4s to about 30s.

The method of producing the tapes of the invention includes weaving afabric with distributed warp yarns with elastomeric cores and other warpyarns with the latter under normal weaving tension and with theelastomeric core yarns at least partially stretched and preferably atdead stretch. The method further includes coating the fabric in fullystretched condition with a pressure sensitive adhesive to produce apressure-sensitive adhesive tape and applying heat to the tape underslack conditions to permit the tape to relax and become nonplanar. Arelease coating may be applied to the backing fabric to enhanceunrollability preferably when the latter is fully stretched at any pointeither prior to layer coating with adhesive or afterwards.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, a roll 10 of a typical elasticpressure-sensitive adhesive tape of the invention is illustrated woundover the core 14. The woven backing 11 has distributed warp yarns withelastomeric cores. These distributed warp yarns preferably occur in arepeating pattern of distribution but they may be mixed in proper ratioindiscriminately with other warp yarns, their exact distribution beingindeterminate but predictable by statistical methods. The elastomericcore yarns cause the backing when relaxed to assume a nonplanarcharacter including intermingled raised and depressed areas 16 and 17.The pressure-sensitive adhesive coating 12 also has raised and depressedareas and optionally may have small areas 15 devoid of adhesive whichpermit the tape to breathe. The loose relaxed winding of the roll 10 isshown at the cut end 13 which in this embodiment has a corrugatedappearance.

FIG. 2, a typical stretched fabric 20 useful in the manufacture ofproducts of the invention is illustrated. Warp yarns 21 are preferablyof stretch nylon but other yarns might be substituted to give somewhatdifferent properties to the product. Warp yarns 22 are preferablycorespun spandex with the spun portion of rayon but other spun coveringsor yarn wrappings may be used to protect the spandex or other syntheticor natural elastomer core. Warp yarns 23 are preferably spun rayon butmay be any other spun yarn or multifllament yarn. Filler yarns 24 arepreferably of cotton but rayon or other natural and synthetic yarns maybe utilized.

FIG. 3, another typical fabric 30 useful in the manufacture of theproducts of the invention is illustrated. In this illustration thefabric is shown stretched with warp yarns 31 being preferably of stretchnylon, warp yarns 32 being covered spandex yarn, and warp yarns 33 beingpreferably of spun rayon. Picks 34 are of doubled yarn, preferably ofcotton.

FIG. 4 illustrates still another typical fabric 40 useful in themanufacture of products of the invention in its stretched condition.Warp yarns 41 are preferably of stretch nylon while warp yarns 42 arecovered elastomeric yarns preferably spandex covered with a spun rayoncovering. It is to be noted that warp yarns 42 have floats 45 on oneside of the fabric, which side ultimately will be that which receivesthe pressure-sensitive adhesive. Warp yarns 43 are preferably of spunrayon while filler yarns 44 are preferably of cotton.

FIG. 5 illustrates isometrically a relaxed portion 50 of the fabric ofFIG. 3 coated with adhesive 51. 1t should be noted that elastomeric warpyarns 32 although considerably relaxed are still taut and tend to resistdisplacement from the linear position as opposed to the other warp yarnswhich are either slack as with rayon yarns 33 (or with other nonstretchwarp yarns which might be used instead, the slack being caused byretraction of the elastomeric yarns), or, as with warp stretch yarnssuch as nylon stretch yarns 31, are readily displaced even when the yarnis not slack. As a consequence the picks 34 tend to lie either in raisedposition or depressed position with respect to the elastomeric yarns.When picks lie entirely on one side or the other of the elastomericyarns in the fabrics of this invention, transverse ridges 53 and 54 andvalleys 52 appear when the fabric relaxes and the corrugated appearancesuch as is illustrated in FIG. 1 is evident. Pressure-sensitive adhesive51 which presents a flat surface as applied when the fabric is at deadstretch, follows the contours of the fabric when the latter retracts.The adhesive also assumes a corrugated appearance when applied tobacking of this construction. It is evident that the corrugatedappearance is emphasized by the use of dual picks in the fabric of F IG.5.

There is some advantage in rewinding in that roll 75 can become quitelarge before it is replaced and somewhat greater care in final windingon the shorter rolls can be exercised.

Pressure-sensitive adhesives suitable for the tapes of this inventionare not critical. Any of the well-known adhesives employed forpressure-sensitive adhesive tapes are suitable and may be utilized. Itis preferred, however, that the adhesive not be applied directly to thewoven backing in thin solvent solu-- tions because of the tendencyinherent in such solutions for soaking into the interstices and even thefibers of the wove: materials. Calendering is the preferred method ofapplying the adhesive directly to the backing but other procedures whichinvolve applying the adhesive in relatively viscous form may beemployed. For instance, if the adhesive is not spread directly fromsolution onto the woven backing, even a solvent spreading technique maybe employed. This is accomplished by the well-known transfer techniquein which the adhesive is applied from a solvent solution onto atemporary backing such as a slip sheet or peel surface to which it hasrelatively low adhesion. Polyethylene film and silicone coated sheetshave been employed for this purpose. The dried and now viscous layer oftacky adhesive, carried on its temporary backing, is then applied to itspermanent backing in adhesive contact. The composite is pressed togetherusually by being passed through the restricted nip of two rubber squeezerolls or in some cases between steel rolls. The adhesive now is muchmore firmly united to its permanent backing than to the temporary slipsheet, which latter may be peeled offwhen it is convenient, ex posingthe adhesive surface with the adhesive intact and adherent to thebacking. With respect to this invention, if the optimum stretch is to berealized, the adhesive should be applied to its permanent backing whilethe latter is substantially at dead stretch, after which the tape shouldbe relaxed in the usual way.

A suitable typical pressure-sensitive adhesive for use in preparing thetapes of this invention is as follows:

Ingredients Parts by Weight If the same picks are caused to appear onopposite sides of adjacent elastomeric warp yarns, a pebbled surfacerather than a corrugated surface will result. Likewise, interruptedridges may be produced by causing the picks to appear on the same sideof several consecutive elastomeric yarns and then to appear on theopposite side of several next consecutive elastomeric yarns.

One may also vary the surface rugosities by employing floats in the warpyarns. Thus, in FIG. 4 the elastomeric warp yarns 42 are caused to floatacross certain picks. When, as is illustrated, the same picks arefloated across with the elastomeric warp yarns, a very definitetransverse rib effect is achieved in the relaxed fabric which ispreferably woven with the elastomeric warp yarns at dead stretch. Whenthe elastomeric yarn is the float yarn, the rib effect is morepronounced before the fabric is coated with the adhesive thansubsequently even after the coated fabric is permitted to relax. Otherwarp yarns than the elastomeric yarn obviously may be floated on theadhesive side or on both sides. These latter variations do have aneffect on the degree of interweaving, and when the elastomeric warp isnot floated, do affect the relaxed surface contour to an appreciableextent. But when the elastomeric warp yarns are floated across severalpicks, their effect on the surface contour is the predominant effect.

FIG. 6 illustrates apparatus useful in practicing a typical method ofthe invention to produce the products of the invention. A calender 60equipped with rolls 61, 62 and 63 is used to extrude a sheet 66 ofpressure-sensitive adhesive mass about 3 to 10 mils thick and preferablyabout 4.5 mils thick from a bulk 65 onto roll 62, where it contactsuncoated or release coated backing fabric 64 in the fully stretchedcondition. The adherent layers pass through the nip 77 with the gap setpreferably at about 1.5 mils plus the thickness of the stretchedbacking. The adherent tape 68 is scraped from roll 62 by the hot doctorblade 67. The tape then passes over a roller 69 and between moist or dryheating means preferably two steam jet banks 70 and 71 as illustrated,where the adhesive tape relaxes from its fully stretched condition. ithangs in the loop 72 to substantially remove tension. it then passesover roll 73 and is wound up on roll 75. If the tape is not to berewound into shorter length rolls, roll 75 may be wound on its permanentcore and the tape cut into proper widths directly through tape and core.When this is done and a release coating is desired, it may be applied tothe preferably stretched backing either before or after the applicationof pressure-sensitive adhesive. When the tape is to be rewound, however,a sheet of facing material 76 from the roll 74 is interposed between theadhesive and the backing.

The woven fabric backing materials of the products of the invention intheir relaxed state weigh in the range of to 300 grams per square yardand are substantially nonplanar with intermingled raised and depressedsurface portions which substantially disappear when the fabric is fullystretched. The fabric is very readily stretched to a length at least 2.2times its unstretched relaxed length by a force of about 0.3 to 1.0pounds per inch width. The stretched fabric has the open appearance ofgauze but differs from gauze in that the fabric includes distributedamong other warp yarns, elastomeric yarns which preferably are corespun,the material of the spun portion not being critical. Optionally theelastomeric core may be covered by a wrapping of one or two helicalwindings of yarn. The covering may be of cotton, rayon, nylon or anumber of other synthetic materials in spun or yarn form. Backingmaterials of this invention are woven with the elastomeric warp yarns inthe stretched condition and preferably in the fully stretched conditionreferred to as dead stretch." The other warp yarns are woven with theusual tension. The material and structure of these other yarns is notcritical to the invention but certain warp yarns supplementing theelastomeric warp yarns may be preferred for one end use while other warpyarns may be preferred for another end use. Thus, if one of therequisite characteristics is transverse handtearability, thesupplementary warp yarns might be of a material such as rayon which canbe torn across readily. Or if high tensile strength is a requisiteinstead of tearability, one might utilize fine spun glass warp yarns orperhaps multifilament or monofilament nylon as the yarns supplementaryto the elastomeric warp yarns. For softness one might select spun yarns.Thus the warp yarns supplementary to the elastomeric warp yarns shouldbe selected from those yarns which give a desired result and which arecapable of easy flexing so that the elastomeric yarns will not bematerially restrained from retracting after being stretched. Theelastomeric yarns should be distributed about every third warp yarn toabout every sixth warp yarn across the width of the backing with thepreferred distribution one of every four.

One can adjust the amount of retractive force which the fabric has byvarying the warp ratio soas to increase or decrease the proportion ofelastomeric warp yarns to the supplementary warp yarns. Another methodis to modify the denier or the composition of the elastomeric core.Preferred elastomeric core material is spandex but natural rubber orsynthetic rubbers other than spandex may be used satisfactorily. Thepreferred core denier is about 70 but may range from 40 denier to 140denier. A rayon-covering spun to produce a 30/ l corespun yarn ispreferred. The combined warp ends per inch range from about 18 to about40 with the preferred yarns equivalent in size to 30's cotton yarn. Warpyarn equivalent sizes as coarse as cotton 's and as fine as cotton 120smay be utilized in certain embodiments depending upon the strength andother required specifications and the yarn material being utilized.

With regard to FIG. 4, a yam 43, preferably spun rayon, is shown on eachside of each elastomeric yarn 42. At the point where the float in yarn42 occurs, the two yarns 43 on either side of yarn 42 are in the sameshed. If desired this may be avoided very readily by reversing the shedof the three warp yarns to the right of each odd elastomer yarn. Othermodifications of the weave of FIG. 4 may be employed to increase theinterlacing of the yarns.

In processing the tapes of this invention, if calendering is the methodutilized as is preferred, a three or four roll calender may be employed.The three roll calender method is illustrated in FIG. 6. If a four rollcalender is utilized, it may be expedient to lead the cloth at the rightover the fourth roll and between the nip of this fourth roll and thecenter roll. Referring to FIG. 6, the range of temperatures on the toproll 61 are from about 240 to 270 F. with a preferred top rolltemperature of 260 F. The range of temperatures for the center roll 62are about 190 to 200 F. with a preferred center roll temperature of l90F. The bottom roll 63 temperature range is about 180 to 210 F. with apreferred temperature of 200 to 210 F. In practice the cloth is causedto enter the calender at dead stretch, the nip between the center andbottom roll being open the thickness of the stretched cloth plus about1.5 mils. The nip between the top and center roll is preferably set toextrude a sheet of pressure-sensitive adhesive about 4.5 mils thick ontoroll 62. All but 1% mils of this mass is thus pressed into the fabricwith the remainder on the surface between the roll and the backing. Thetape thus created moves adherent to the roll until it is scraped cleanfrom adhesive contact with the center roll by the hot doctor blade 67which should be heated in the temperature range of about 225 to 325 F.,preferably at about 300 F.

After leaving the calender, the adhesive coated backing is preventedfrom relaxing to some extent by the adhesive. It is necessary, to getmaximum elasticity in the tape, to warm the tape to permit it to relaxand to that end steam at 180 F. or more or hot gas or other heat may beutilized. If the tape is to be rewound, the adhesive is faced with aslip sheet preferably when the tape is in its relaxed condition butalternatively the slip sheet facing may be applied during or just afterthe calendering operation, the tape with the slip sheet now attachedbeing relaxedas before. A completely suitable slip sheet facing for thispurpose is a product sold by Brown Company, Kalamazoo, Michigan, calledVegetable Parchment." This is designated 35 pound P.L. crinkled 946treated. The treatment is on both sides with a silicone resin.

The faced adhesive products of this invention may be sold in rolls,strips or sheets, with any necessary trimming being expedited andimproved by chilling the tape to the point where the adhesive may be outwithout smearing. But the preferred products of this invention are thosewhich may be unrolled readily from a roll in which the back of thebacking and the adhesive are in contact. The rugose character of thebacking and the adhesive in contrast to the substantially planarcondition immediately after calendering due largely to relaxation of thefabric before rolling, is definitely helpful in the problem of adhesionof the tape to its own backing and permits unrolling with theapplication of reasonable unrolling force. The

Ingredient Parts by Weight Polyethylene emulsion (4l% solids) l0.8Distilled water 212 Methocel (4,000 c.p.s. granular mc. standard) 0.9

The emulsion is diluted by the water and the methocel is sifted in andpermitted to dissolve to prepare the coating emulsion for the reverseroll spreader.

In practice the gap on the reverse roll spreader is set at about 5 mils.The coated spreader roll and the tape backing are in contact but movingin opposite directions at relative speeds such that the release emulsionis wiped ofi preferably only on the ridges and raised portions of thebacking. The ridge-coated backing or, as the case may be, the faced orunfaced adhesive tape then passes through an oven which drys and fusesthe polyethylene emulsion into film patches largely adherent to theraised portions of the backing. The adhesive tape in large faced rollsis then cut into appropriate lengths and preferably laid in flat stripsto relax, adhesive side up as the facing is removed. A plastic core isthen placed transversely at the end on the exposed adhesive and the tapeis rolled onto the tube core. The rolled tape, which is the width of thefabric, is then sliced through core and tape into individual rolls ofthe required width. Some of the more modern apparatus will do a cleanjob of adhesive tape roll slicing at ambient temperatures but on olderequipment roll slicing may be expedited and the roll quality may beimproved by chilling or even freezing the rolls prior to slicing intothe required roll widths. Tapes formed in accordance with the hereindescribed method may be stretched in the range of 40 to 50 percent withrapid recovery to substantially their original length after removal ofthe stretching forces.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments ofthe conformable elastic adhesive tapes of the invention have elasticwoven backings of the general-type illustrated in FIG. 4, weighing whenrelaxed in the range of to 300 grams per square yard. The elastomericwarp yarns of the backing are 30's corespun yarns with a 70 denierspandex core and spun rayon covering. The other warp yarns are 70/2snylon stretch yarn and 30s spun rayon yarns. The nylon warp yarns andthe elastomeric warp yarns are separated by a spun rayon warp yarn sothat out of every four warp yarns, two are spun rayon, one is a nylonstretch yarn, and one is a corespun elastomeric yarn. The fabric iswoven with 32 ends per inch at dead stretch for the elastomeric warpyarns and at normal warp tension for the other warp yarns. Theelastomeric yarns float across the same five picks on the side of thefabric which ultimately will be coated by the pressure-sensitiveadhesive and then pass over and under a single pick and again over fivepicks. This pattern is repeated. All the other warp yarns are woven lXlbut the three warp yarns to the right of each odd elastomeric warp yarnhave their sheds reversed from those illustrated in FIG. 4. The filleryarns are cotton 10/ l s with a pick count of 32 picks per inch. Acoating of pressure-sensitive adhesive originally 4.5 mils in thicknessof the formula set forth in the specification is adherent to thebacking, the total thickness of the tape at dead stretch being 1 /2 milsplus the thickness of the backing. The backing is coated with a driedand fused releme coating of polyethylene emulsion of the formula setforth in the specification, the release coating being mostly present onthe raised portion of the backing. The tape is relaxed with the majorsurfaces of the backing assuming a nonplanar appearance and the adhesivesurface reflecting, to a degree, the

underlying backing rugosity. The tape is stretchable to a length between140 and 150 percent of its relaxed length, is

conformable, breathable, readily tearable by hand transversely, andreadily unrollable from roll form when the adhesive is in contact withthe back of its own backing.

The preferred method of the invention is a method including the steps ofweaving the backing material from the components indicated in thepreferred product embodiment, coating the fabric with adhesive usingapparatus of the type illustrated in FIG. 6, using roll temperatures asfollows: top roll 260 F.; center roll 190 F.; and bottom roll 200 F.;with the gap between the top and center roll at 4 /2 mils and with abulk of adhesive of the formula set forth in the specification and usinga gap between the center and bottom roll of 1 /2 mils plus the stretchedthickness of the backing. The tape is then relaxed by running it betweensteam jets with steam at, at least, 180 F. The tape is then faced asindicated in FIG. 6 with Vegetable Parchment," is back coated with thepolyethylene release coating using a reverse roll spreader with the gapat mils, is dried and fused in an oven at about 250 F the facing isremoved and the tape spread flat in roll length adhesive side up. lt isloosely rolled into rolls, chilled and cut into the desired widths.

lclaim:

l. A conformable, elastic, permanently tacky, pressure-sensitiveadhesive tape comprising an elastic backing formed of interwoven warpand filling yarns and weighing when relaxed in the range of 100 to 300grams per square yard, elastic warp yarns comprising elastomericfilaments distributed across the width of said backing and interspersedwith nonelastomeric textile warp yarns in the ratio range of anelastomeric filament warp yarn every third warp yarn to an elastomericfilament warp yarn every sixth warp yarn, said warp yarns extendingparallel to the longitudinal extension of said tape, filling yarns insaid backing being nonelastomeric textile yarns extending normal to saidwarp yarns, said elastomeric filament warp yarns when relaxed beingsubstantially shorter than said nonelastomeric warp yarns but having astretched length at least equal to the extended length of saidnonelastomeric warp yarns, the weave of said backing being such thatsaid elastomeric warp yarns are interwoven to provide an average floatlength thereof on at least one side of said backing which exceeds theaverage float lengths for nonelastomeric textile warp yarns of saidbacking whereby said backing when relaxed assumes a surfaceconfiguration in which transverse corrugations occur along saidelastomeric warp yarns, the floats thereof contracting to bridge thevalleys of said corrugations, and a permanently tacky,pressure-sensitive adhesive adherent to one side of said backing withits exposed surface reflecting to a degree the rugosity of theunderlying backing becoming more nearly planar when said tape isstretched and more ru gose as said tape is permitted to relax.

2. The tape of claim 1, wherein the relaxed corrugated surfaceconfiguration takes the form of ridges and valleys extendingtransversely from edge to edge of said tape.

3. The tape of claim 1, having an adhesive side and a nonadhesive sideand rolled, partially relaxed, upon itself, preserving to a degree thetransverse ridges and valleys thereof in the convoluted roll,substantial portions of the nonadhesive side of said tape being out ofcontact with the adhesive side thereof, said substantially reducedcontact enhancing the unrollability of said tape and reducing theprobability of deleterious adhesive delamination.

4. The tape of claim 1, wherein a fully extended length thereof isgreater than percent of the relaxed length thereof.

5. The tape of claim 1, wherein the woven elastic backing,

before coating with adhesive, may be stretched to a length 2.2 times itsrelaxed length with a stretching force applied warpwise offrom about 0.3to 1.0 pounds per inch width,

6. The tape of claim 1 wherein the warp yarns of the woven elasticbacking are equivalent in size to cotton 30s and the filling yarns areequivalent to cotton 10's.

7. The tape of claim 11 wherein the warp yarns other than those withelastomeric cores are stretch nylon.

8. The tape of claim I wherein the side edges are smooth out and ravelresistant.

9. The tape of claim 1 wherein the elastomeric warp yarns of the wovenelastic backing float across a plurality of successive picks on theadhesive side.

10. The method of producing a conformable elastic permanentlypressure-sensitive adhesive tape comprising forming a fabric byinterweaving textile filling yarns with warp yarns consisting ofstretched elastomeric yarns interspersed with normally tensioned textileyarns in a weave such that the stretched elastomeric warp yarns have anaverage float length on at least one side of said fabric which exceedsthe average float length of other warp yarns on that side, layer-coatingsaid fabric in the fully stretched condition with a permanently tacky,pressure-sensitive adhesive to produce an adhesive tape, subjectingportions of said tape, while spacially free to retract, to temperatureswhich soften said adhesive, whereby retraction of said elastomeric warpyarns occurs, said retraction forming said tape surfaces into aconfiguration in the form of transverse ridges and valleys therebyimparting enhanced elasticity and conformability to said tape.

11. The method of claim 10 wherein the layer coating withpressure-sensitive adhesive is a calendering method.

12. The method of claim 10 wherein the elastomeric core yarns are fullystretched when the fabric is woven.

13. The method of claim 10 wherein the fabric is back coated with aninterrupted coating to which the adhesive has reduced adhesion androlling said tape into adhesive rolls.

14. The method of claim 10 wherein the elastomeric core yarns are wovenwith a predominance of warp yarns of the weakness of 30s spun rayon.

15. The method of claim 10 wherein the elastomeric core yarns are wovenwith a predominance of warp yarns of the strength of 70/2 stretch nylon.

2. The tape of claim 1 wherein the relaxed corrugated surfaceconfiguration takes the form of ridges and valleys extendingtransversely from edge to edge of said tape.
 3. The tape of claim 1,having an adhesive side and a nonadhesive side and rolled, partiallyrelaxed, upon itself, preserving to a degree the transverse ridges andvalleys thereof in the convoluted roll, substantial portions of thenonadhesive side of said tape being out of contact with the adhesiveside thereof, said substantially reduced contact enhancing theunrollability of said tape and reducing the probability of deleteriousadhesive delamination.
 4. The tape of claim 1 wherein a fully extendedlength thereof is greater than 135 percent of the relaxed lengththereof.
 5. The tape of claim 1 wherein the woven elastic backing,before coating with adhesive, may be stretched to a length 2.2 times itsrelaxed length with a stretching force applied warpwise of from about0.3 to 1.0 pounds per inch width.
 6. The tape of claim 1 wherein thewarp yarns of the woven elastic backing are equivalent in size to cotton30''s and the filling yarns are equivalent to cotton 10''s.
 7. The tapeof claim 1 Wherein the warp yarns other than those with elastomericcores are stretch nylon.
 8. The tape of claim 1 wherein the side edgesare smooth cut and ravel resistant.
 9. The tape of claim 1 wherein theelastomeric warp yarns of the woven elastic backing float across aplurality of successive picks on the adhesive side.
 10. The method ofproducing a conformable elastic permanently pressure-sensitive adhesivetape comprising forming a fabric by interweaving textile filling yarnswith warp yarns consisting of stretched elastomeric yarns interspersedwith normally tensioned textile yarns in a weave such that the stretchedelastomeric warp yarns have an average float length on at least one sideof said fabric which exceeds the average float length of other warpyarns on that side, layer-coating said fabric in the fully stretchedcondition with a permanently tacky, pressure-sensitive adhesive toproduce an adhesive tape, subjecting portions of said tape, whilespacially free to retract, to temperatures which soften said adhesive,whereby retraction of said elastomeric warp yarns occurs, saidretraction forming said tape surfaces into a configuration in the formof transverse ridges and valleys thereby imparting enhanced elasticityand conformability to said tape.
 11. The method of claim 10 wherein thelayer coating with pressure-sensitive adhesive is a calendering method.12. The method of claim 10 wherein the elastomeric core yarns are fullystretched when the fabric is woven.
 13. The method of claim 10 whereinthe fabric is back coated with an interrupted coating to which theadhesive has reduced adhesion and rolling said tape into adhesive rolls.14. The method of claim 10 wherein the elastomeric core yarns are wovenwith a predominance of warp yarns of the weakness of 30''s spun rayon.15. The method of claim 10 wherein the elastomeric core yarns are wovenwith a predominance of warp yarns of the strength of 70/2 stretch nylon.